You both have a path in life that you're supposed to follow, and you find that this relationship isn't necessarily the best at helping either of you, but you especially, find your way along. It's not that you don't get along, or that they intentionally divert your progress in life; it's just that their values are in conflict with where you're going, and to stay together as a couple could mean that you have to make compromises that aren't the best thing for your own life. Think of it this way -- someone whose primary focus in life was family and close, intimate, day-to-day connection would have a hard time supporting a lover who wanted to travel to the ends of the world for their career, right?
This is the type of problem you two face. Neither of you create problems on purpose; there is just be something implicit in the people that you are that makes it hard to move forward in life as a team. If you don't follow your dreams because the relationship is holding you back, it could start to seem as though you're not decisive or ambitious enough. But that isn't the real problem. The real problem is that eventually, you both have to make a choice. Which is more valuable to you -- the relationship as it stands, or your own future as the exact person that you are? The two might be mutually exclusive. You may have to decide to step out of each other's way if you want either of you to be truly happy.